Representatives from seven Colorado River basin states and the U.S. Bureau of Reclamation took part in the joint project, which “did not result in a decision as to how future imbalances should or will be addressed,” the executive summary of the study states, “but provides a common technical foundation that frames the range of potential imbalances that may be faced in the future and the range of solutions.”

“We’ve already been addressing these issues on a Colorado-wide scale,” said Ted Kowalski of the Colorado Water Conservation Board, in statements responding to the study’s release. “Now, with this basin-wide, cooperative effort, we can get a glimpse of the bigger picture and begin to work toward planning for the future, with a well-informed idea of where we’re headed.”[…]

Apportioned water in the Colorado River system exceeds the long-term historical natural flow of about 16.4 million acre feet, and demand for consumptive use is projected to range between 18.1 and 20.4 million acre-feet in 50 years. Projected increases in demand coupled with projections of reduced supply due to climate change created the backdrop of the study. Droughts lasting five or more years may occur 50 percent of the time over the next 50 years. Meanwhile, population in the study area is expected to increase…

But, according to [Eric Kuhn], the study also points to serious problems for the upper basin. Under the climate change scenario depicted, without additional action, the upper basin may experience a future deficit of its compact obligation as often as one in five years by 2040.

“The upper basin is currently unprepared for this possibility,” Kuhn said in statements. “To address an uncertain future, upper basin users will need to develop new risk-management strategies, including improved aggressive conservation, optimal use of storage and water-banking.”

Kuhn further cautions upper basin planners: “The reality may be that new development simply threatens existing water supplies, or that new development may only be available during increasingly rare wet cycles.”

“The Bureau study should not be seen as a green light for unrealistic, expensive and environmentally destructive projects that move water out of their basins of origin,” said Trout Unlimited’s Dave Glenn, who grew up near the Green River in Utah. “TU and other groups have highlighted a range of cheap, pragmatic options — including conservation, reuse and water sharing — that will meet water needs without sacrificing our rivers and outdoor heritage.”